RI_METRIC

Sets up RI metric [Edit on GitHub]

Keywords

CUTOFF_RADIUS

Type: real
Default: 3.00000000E+000 [angstrom]
Usage: CUTOFF_RADIUS 3.0

Description: The cutoff radius (in Angstrom) for the truncated Coulomb operator.

EPS_RANGE

Type: real
Default: 1.00000000E-008

Description: The threshold to determine the effective range of the short range RI metric: erfc(omega*eff_range)/eff_range = EPS_RANGE

OMEGA

Type: real
Default: 0.00000000E+000
Usage: OMEGA 0.5

Description: The range parameter for the short/long range operator (in 1/a0).

POTENTIAL_TYPE

Type: enum
Default: DEFAULT
Usage: POTENTIAL_TYPE DEFAULT

Description: Decides which operator/metric is used for resolution of the identity (RI).

Valid values:

DEFAULT Use Coulomb metric for RI-MP2 and normal-scaling RI-SOS-MP2, RI-RPA and GW. Use Overlap metric for low-scaling RI-SOS-MP2, RI-RPA and GW for periodic systems. Use truncated Coulomb metric for low-scaling RI-SOS-MP2, RI-RPA and GW for non-periodic systems.
COULOMB Coulomb metric: 1/r. Recommended for RI-MP2,
IDENTITY Overlap metric: delta(r).
LONGRANGE Longrange metric: erf(omega*r)/r. Not recommended with DO_SVD .TRUE.
SHORTRANGE Shortrange metric: erfc(omega*r)/r
TRUNCATED Truncated Coulomb metric: if (r < R_c) 1/r else 0. More accurate than IDENTITY for non-periodic systems. Recommended for low-scaling methods.

T_C_G_DATA

Type: string
Default: t_c_g.dat

Description: Location of the file t_c_g.dat that contains the data for the evaluation of the truncated gamma function